It should do about the same as the "oxygen-free copper" cables, perhaps slower - moving bits from A to B.
Is there any evidence otherwise?
Apple doesn't support aptX HD, aptX Lossless, LDAC for Bluetooth devices. IIRC they use AAC 256 kbps for their wireless audio.
Once again, totally fine for listening Spotify and apply music, but I imagine suboptimal for DAW.
It's not as noticeable for people who never talked on a real landline phone (i.e. not VoIP) because everything else has noticeable and often non-constant latency.
Bluetooth also introduces latency. It might be ok for mixing, but it's completely unusable for recording applications.
I use iPad with RME ADI DAC-2 and I can't think of a single issue.
I hope I missed a joke. That is a high end DAC that retails for $1300, and could very well be the best DAC available for less $1500. That'll do nicely. I'd prefer Lavry Engineering's discontinued DA11 (and AD11), but it's somewhat of a judgement call at that level.
iPad can emit material with different sampling rate (haven't verified different bit depth, but I guess, there should be no issues), iPad also knows not to meddle with the software mixing and delegates everything to the DAC. It behaves exactly as I'd like it to behave.
No joke intended. My point was, that if iPad has no issues with this device, then it must be able to drive any other USB Audio Class interface.
It's USB Audio that is special.
> iPad can emit material with different sampling rate (haven't verified different bit depth, but I guess, there should be no issues),
Core Audio is a component of iPadOS and iOS, and along with Core Audio comes everything Core Audio can do.
> iPad also knows not to meddle with the software mixing
Is there an example or anecdote you have in mind of a platform meddling with mixing?
> and delegates everything to the DAC.
It's really USB Audio that is performing these miracles.
Sure, Android resamples everything to 48kHz, uses software mixing. No workaround. GNU/Linux by default does the same with PipeWire, PulseAudio and ALSA (dmix). One can configure it for bitperfect playback though. I can’t say about modern Windows, the last one I used was Windows 7, and by default it resampled everything to 48kHz too.
> USB Audio that is special
The last time I saw a non USB audio class device was some 15 years ago. I frankly do not understand, why are you stressing this so much.
I think the problem here that most won't realize is that they'll have no idea what you're listening to and so will be mixing audio in the dark, so to speak. Professionals will check headphone mixes, but generally won't mix with headphones certainly not bluetooth headphones. I suppose there may exist such a thing as powered Bluetooth monitors, but again, the wireless Bluetooth, and what it does to audio, is the weak part in the chain. iPad built in speakers are not flat, so if you mix for them, the audio might only sound alright coming out of an iPad.
There are probably audio docks for iPad which will include a DAC for converting stereo sound from the iPad USB-C port, and jacks for monitors, but I have never seen one that doesn't have the cheapest components available. Not sure of the current abilities of iPad and USB-C, but last I heard, iPad was only capable of stereo in and stereo out. There's a lot that can be done with just two tracks, but do not doubt that everything depends on the converters and preamps, so a professional quality USB-C ADC/DAC with decent pres (unless off-boarded) is paramount to creating half decent tracks, which is paramount to creating very good mixes.
Not everyone is a professional audio engineer, and everyone here that is an expert at everything will likely be satisfied with terrible converters and the audio they produce. YMMV